HTML5/JS (ES6) "Lunar Lander" game. Pilot a lunar module down the the surface of the moon, firing the boosters as necessary (touch screen, hold mouse button, or depress any key) to touch down at a safe speed of 4 m/s or less without running out of fuel. Fuel represents about half of the weight of the lunar module and so burning fuel reduces your inertia.
Designed as an experiment into very-simply adapting HTML5 canvas games to work in different resolutions and on a variety of devices. Port/reimagining of a project I wrote in Turbo Pascal in 1997, during my A-levels.
For more details, see https://danq.me/2018/03/03/lunar-lander/.